Storage to floor space ratio in a semiconductor factory requires a high density storage system. Known systems utilize an overhead transporter to transfer substrate carriers to stockers and a robotic system to then transfer the substrate carriers from the overhead transporters to storage areas in a stocker. The robotic system typically includes a large multi-axis robotic mechanism which, among other things, takes up valuable storage space.
Semiconductor factories require highly efficient storage for work in progress (WIP) to maximize their return on capital investment. Existing storage solutions of the type discussed above waste valuable storage space and typically require three main steps to store a container: (1) OHT to conveyor; (2) conveyor to crane; and (3) crane to shelf.
What is needed is a simple, reliable, and/or cost effective system and one which will increase substrate carrier storage per square foot more than is available with current systems.